Deer acquire prions, the infectious agents behind Chronic Wasting Disease (CWD), primarily through exposure to contaminated environments and direct contact with infected animals. This exposure can occur via bodily fluids like feces, saliva, blood, or urine, either through direct contact with an infected deer or indirectly through contact with contaminated soil, food, or water. The insidious nature of prions allows them to persist in the environment for extended periods, contributing to the ongoing spread of CWD.

Direct contact between deer, especially during social behaviors like grooming or aggression, can facilitate prion transmission through saliva, blood, or other bodily fluids. Mother deer can also transmit prions to their fawns during nursing or through placental fluids during gestation. The close proximity and frequent interactions within deer populations contribute to the ease of direct transmission, especially in areas with high deer densities.

The decomposition of infected deer carcasses releases large quantities of prions into the environment. Scavengers feeding on these carcasses can further spread the prions through their feces, contaminating new areas. This highlights the importance of proper carcass disposal in managing CWD. State wildlife agencies often recommend specific disposal methods, such as incineration or burial in designated landfills, to minimize environmental contamination.

Research suggests that some deer may be genetically more susceptible to CWD than others. Genetic variations in the prion protein gene (PRNP) can influence the incubation period and the likelihood of developing the disease. Understanding these genetic factors is crucial for developing targeted management strategies.

https://enviroliteracy.org/how-do-deer-get-prions/